Is Pyrex Microwave Safe? A Comprehensive Guide to Safe Cooking Practices

As microwave ovens have become a common and indispensable fixture in every modern kitchen, it is essential to understand if the kitchenware being used will stand up to the test in terms of safety and reliability. One of the most popular choices for many home cooks and professional chefs alike is Pyrex, a versatile and durable glassware collection found in countless homes worldwide. As the oven-safe properties of Pyrex are lauded by many, a question must be addressed – is Pyrex microwave safe?

This article will provide a comprehensive guide to help demystify the facts surrounding the safety of using Pyrex in microwaves, delving into the science behind the manufacturing process and identifying important precautions to take when using these popular glassware products. Moreover, we will examine the transition from traditional Pyrex to contemporary models and discuss any potential impact on microwave safety.

What is Pyrex?

What is Pyrex

As a cooking enthusiast, I have always been curious about the different cookware available in the market. One name that has popped up quite frequently is Pyrex. But what exactly is Pyrex, and why is it so popular among home cooks and professional chefs alike? First, Pyrex is a brand of glassware that has been around for over a century. It was invented by a scientist named Jesse Littleton and his wife, Bessie in 1915. Pyrex was originally intended for use in laboratories, but it quickly gained popularity among home cooks due to its unique properties.

One of the main benefits of using Pyrex is its ability to withstand extreme temperatures. Unlike traditional glassware, Pyrex can go from the freezer to the oven without cracking or breaking. This makes it perfect for storing and reheating leftovers and baking casseroles, pies, and other dishes.

Another advantage of Pyrex is its non-reactive nature. Unlike metal or plastic cookware, Pyrex won’t react with acidic or alkaline ingredients, which can affect the taste and quality of your food. This means you can use Pyrex to cook acidic dishes like tomato-based sauces without worrying about the pot reacting with the ingredients.

Pyrex is also a great choice for those concerned about their health and the environment. Unlike plastic containers, Pyrex is completely free of harmful chemicals like BPA (bisphenol A) and phthalates. It’s also reusable, which reduces waste and helps to minimize your carbon footprint.

In addition to its practical benefits, Pyrex is also aesthetically pleasing. Its clear glass design allows you to see your food as it cooks, which can be helpful when you’re trying to achieve the perfect texture and color. Pyrex also comes in a variety of shapes and sizes, making it easy to find the perfect container for your needs.

Different Types of Pyrex Dishes

Different Types of Pyrex Dishes

Pyrex Glass Jug

This type of Pyrex dish is perfect for making and serving drinks. Whether you’re making iced tea, lemonade, or a pitcher of margaritas, a Pyrex glass jug is a great choice. The clear glass lets you see the contents inside, and the sturdy handle makes it easy to pour.

Pyrex Bowl

Pyrex bowls come in various sizes and are perfect for mixing ingredients. Whether mixing up a batch of cookie dough or tossing a salad, Pyrex bowls are a great choice. They’re easy to clean and can also be used for serving.

Vintage Pyrex

Collectors and enthusiasts highly seek after Vintage Pyrex dishes. These dishes were made in the mid-20th century and come in various colors and patterns. Whether you’re looking for a classic Pyrex mixing bowl or a rare Pyrex casserole dish, vintage Pyrex is an excellent choice for collectors and home cooks alike.

Can Pyrex Go In Microwave?

Can Pyrex Go In Microwave

It can! Pyrex is made of tempered glass, which means it can withstand high temperatures and sudden changes in temperature without shattering. Ensure the dish is microwave-safe, avoid metal accents, and be cautious when handling hot dishes.

Is Pyrex Microwave Safe?

Pyrex is indeed safe for use in the microwave. Pyrex is made from tempered glass, designed to withstand high temperatures and thermal shock. It can go from hot to cold (or vice versa) without cracking or breaking.

Pyrex glass is considered microwave safe, but there are important conditions to bear in mind while using it. Before buying Pyrex products, take note of the Pyrex logo. PYREX® spelled with capital letters, is the safest borosilicate. It indicates either a vintage Corning Glass Works or a new French product. Pyrex glassware made in the USA or, lately, China is made of high-quality tempered glass.

The manufacturer advises not to shock the glass by putting it in water or on cold surfaces immediately after heating. Any glass product can experience thermal shock when subjected to rapid changes in temperature. Exposing Pyrex glass to rapid temperature changes fails to handle the stress involved with the uneven expansion. This situation may lead to a breakage or burst.

However, if you use Pyrex glass in a microwave and follow the manufacturer’s recommended guidelines, there is no need to worry about explosion or breakage.

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Can You Use Pyrex In The Microwave For Cooking Or Just Reheating?

You can use it for cooking, as well as reheating. Pyrex is microwave safe, as long as it’s not heated for too long or at too high a temperature.

Following a few guidelines is important if you’re using Pyrex for cooking in the microwave. First, make sure the dish is clean and dry before using it. Any moisture or food particles can cause the dish to crack or shatter.

Second, don’t use Pyrex in the microwave for extended periods. It’s best to cook in short increments, stirring or checking the food frequently to ensure it cooks evenly.

Third, avoid using Pyrex in the microwave for high-heat cooking, such as frying or grilling. The high temperature can cause the glass to crack or shatter.

Are There Any Pyrex Products That Are Not Safe For The Microwave?

Due to thermal shock. The sudden and extreme temperature change can cause the glass to break or shatter. Therefore, it is essential to gradually preheat Pyrex dishes before microwaving them.

Additionally, hot Pyrex dishes should not be placed on cold surfaces, and cold Pyrex dishes should not be exposed to high heat in the microwave. These precautions must be taken to prevent damage to the Pyrex and ensure safety in the kitchen.

Do Pyrex Plastic Lids Contain BPA Microwave Safe?

According to a statement released by Pyrex, their plastic lids are free of BPA, making them safe for use in the microwave. BPA, a chemical commonly found in plastics, has been linked to health concerns such as hormone disruption, cancer, and developmental disorders.

Pyrex assures customers that their plastic lids are made with materials that comply with FDA regulations and are designed to withstand microwave heat safely.

Is Pyrex Made From Borosilicate Glass Microwave Safe?

Take note of the Pyrex logo before purchasing, indicating whether the product is borosilicate or tempered glass. PYREX® with capital letters is the safest choice as it is made of borosilicate glass, while American Pyrex is made of tempered glass. Borosilicate glass is known for its resistance to thermal stress, making it perfect for microwaving.

However, following the manufacturer’s instructions when microwaving Pyrex is essential, such as heating the dish for 30 seconds to 1 minute before adding food and using a moderate power setting to prevent overheating.

How Long Can You Safely Use Pyrex In The Microwave?

According to the manufacturer, Pyrex dishes are microwave safe, but there are a few things to keep in mind. Each piece of Pyrex glassware is tested before it is introduced into the market, with rigorous testing lasting around 1000 hours. This means that Pyrex products are designed to be safely used in the microwave. There is no set time limit for how long you can safely use Pyrex in the microwave.

However, following the manufacturer’s recommendations is important, and not exposing cold Pyrex to high heat in the microwave or hot Pyrex to cold surfaces after microwaving, as this can cause the glass to crack or shatter.

What Temperature Range Is Safe For Pyrex In The Microwave?

It is important to note that Pyrex glass dishes should not be exposed to rapid temperature changes, which can lead to thermal shocks and potential breakage. The microwave’s temperature range safe for Pyrex is below the melting point of type 7740 Pyrex, which is 1510°F or 820°C.

Normal home kitchen appliances, including microwaves, do not typically reach this high of a temperature, so melting is not a concern when microwaving Pyrex. As long as Pyrex products are used safely and appropriately, they are a reliable and practical choice for microwave use.

Disadvantages of Using Pyrex in the Microwave

Disadvantages of Using Pyrex in the Microwave

  1. Thermal Cracks: Pyrex is made to withstand extreme temperatures, but sudden changes in temperature can cause it to crack. When moving Pyrex cookware from the fridge or freezer, it’s essential to let it reach room temperature before using it in the microwave to avoid thermal cracks.
  2. Explosions: If Pyrex is not handled correctly, it can explode in the microwave. This happens when a single spot in the dish overheats due to uneven heating, causing the Pyrex to burst.
  3. Not BPA-Free: Some Pyrex products come with plastic lids. These lids may contain the chemical BPA, which can be harmful to human health if ingested through food. Checking the packaging and ensuring the lids are BPA-free before using Pyrex products in the microwave is advisable.
  4. Fragile: Despite being made from heat-resistant glass, Pyrex cookware can be quite fragile, and dropping it or banging it against hard surfaces can cause it to break. This is especially true when it has been subject to repeated use in the microwave.
  5. Uneven Heating: Glass is not a great conductor of heat, meaning it can be difficult to achieve even heating in Pyrex cookware. This can result in some parts of the food being overcooked while others remain undercooked, affecting the overall taste and texture of the dish.
  6. Time-Consuming: Due to its fragile nature and the need to ensure proper temperature changes, Pyrex cookware can be time-consuming to use in the microwave. This is especially true when compared to plastic or ceramic microwave-safe containers that can be quickly reheated or cooked in a fraction of the time.
  7. Limited Versatility: Pyrex may be safe for the microwave, but it is not suitable for cooking methods such as broiling or grilling. This limits its versatility in the kitchen, and users may find themselves needing to purchase other cookware options to achieve these cooking methods effectively.

What Is Pyrex Thermal Shock And How Does It Relate To Microwave Use?

Thermal shock occurs when there is a sudden and drastic change in temperature. This happens because glass is not a good conductor of heat, meaning that when one part of the glass is heated or cooled rapidly, it expands or contracts at a different rate. This uneven expansion or contraction can cause the glass to crack or shatter.

Now, let’s talk about how this relates to microwave use. Microwaves emit electromagnetic waves that excite the molecules in the food, causing it to heat up. This means the glass container holding the food will also heat up from the inside out. If the container is not designed to handle sudden temperature changes, it can break or shatter when you remove it from the microwave or place it on a cold surface.

What Are The Safety Guidelines For Using Pyrex In The Microwave?

Some important safety guidelines to follow when using Pyrex in the microwave.

1. Check for damage: Before using any Pyrex in the microwave, it’s important to check for any cracks, chips, or other damage. Pyrex that is damaged in any way can shatter or break during use, which can be dangerous.

2. Avoid sudden temperature changes: If you’re using Pyrex in the microwave, it’s important to avoid it. For example, don’t remove Pyrex from the freezer; immediately put it in the microwave. Instead, let it come to room temperature first.

3. Use microwave-safe covers: If you’re covering your Pyrex dish in the microwave, ensure you’re using a microwave-safe cover. Pyrex lids are microwave-safe, but other types of covers may not be.

4. Use oven mitts: Pyrex dishes can become very hot in the microwave, so use oven mitts or pot holders to handle them. Avoid touching them directly with your hands.

5. Don’t use metal utensils: Never use metal utensils with Pyrex in the microwave. Metal can cause sparks and damage the Pyrex dish.

6. Don’t overheat: Finally, avoid overheating your Pyrex in the microwave. Pyrex can handle high temperatures but can crack or shatter if it gets too hot. Follow the cooking instructions carefully and use a thermometer to ensure your food is cooked to the proper temperature.

How Can You Tell If Your Pyrex Is Microwave Safe?

How Can You Tell If Your Pyrex Is Microwave Safe

The easiest way is to look for a label or stamp on the glass. If your Pyrex is microwave safe, it should say so somewhere on the product. This could be in the form of a “microwave safe” label or “Pyrex” with a note that it is safe for use in the microwave. Additionally, newer Pyrex products made from borosilicate glass may have a stamp that says “made in the USA” or “made in France.”

If your Pyrex has no labeling or stamp, the next best thing is to check the manufacturer’s website. Most manufacturers will have information about their products’ microwave safety listed on their websites. If you can’t find any information online, it’s best to err on caution and assume your Pyrex is not microwave safe.

If you’re unsure whether your Pyrex is microwave safe, you can try a few additional tests. First, fill a Pyrex container with water and microwave it for one minute. If the Pyrex feels hot, but the water stays cool, it’s likely microwave-safe. If the water heats up along with the Pyrex, it may not be safe for use in the microwave.

Alternatively, you can try tapping the Pyrex gently with a metal utensil. If the Pyrex makes a high-pitched sound, it’s likely made from borosilicate glass and is microwave safe. If it makes a dull sound, it may not be safe for use in the microwave.

Where Can One Find Official Information On Pyrex’s Microwave Safety?

Look for the microwave-safe symbol on the bottom to determine if your Pyrex dish is microwave safe. This symbol looks like a microwave with some wavy lines next to it. If you see this symbol, your Pyrex dish is microwave-free.

If you do not see the microwave-safe symbol on your Pyrex dish, then you should not use it in the microwave. Instead, you can use it in the oven or for storage purposes.

Another excellent resource for information on Pyrex’s microwave safety is the Pyrex website. Here, you can find a wealth of information on the different types of Pyrex products and their recommended uses. They also have a customer service team that can answer any questions you may have about the safety of their products.

How Long Can You Safely Microwave Pyrex?

How Long Can You Safely Microwave Pyrex?

According to the manufacturer, Pyrex dishes are safe for use in the microwave, but certain precautions should be taken to avoid breakage. One should never expose cold Pyrex to high heat or place a hot Pyrex dish on a cold surface after microwaving.

All glass products experience thermal shock when exposed to rapid temperature changes. It is recommended to heat Pyrex dishes at a lower power level for extended periods to prevent thermal stress. Following these guidelines, Pyrex can be safely microwaved for a reasonable amount without any adverse effects.

How To Clean Pyrex?

Step 1: Soak the Pyrex

The first step in cleaning Pyrex is to soak it in warm, soapy water. This will help to loosen any food or grease stuck in the dish. Use mild dish soap, as harsher cleaners can damage the glass. Let the Pyrex soak for at least 30 minutes or longer if needed.

Step 2: Scrub the Pyrex

After the Pyrex has soaked, it’s time to scrub it clean. Use a soft-bristled brush or sponge to gently scrub the dish, careful not to scratch the glass. You can use a paste made from baking soda and water for tougher stains. Apply the paste to the stain and let it sit for a few minutes before scrubbing.

Step 3: Rinse and Dry the Pyrex

Once the Pyrex is clean, it’s important to rinse it thoroughly with warm water to remove any soap residue. Then, dry the dish with a soft, lint-free cloth. Avoid using paper towels or abrasive materials, as they can scratch the glass.

Additional Tips:

  • Avoid exposing Pyrex to extreme temperatures, such as hot ovens or freezers, as this can cause the glass to shatter.
  • If you have a particularly stubborn stain, try soaking the Pyrex in vinegar and water for a few hours before scrubbing.
  • Always handle Pyrex carefully, as it can be fragile and prone to breaking.


Will Pyrex Melt In The Microwave?

According to the manufacturer, Pyrex is made of borosilicate glass and is designed to withstand high temperatures.

The melting point of type 7740 Pyrex is 1510°F or 820°C, which is well above the temperature reached by a typical home kitchen appliance such as a microwave. Therefore, it is safe to say that Pyrex will not melt in the microwave under normal circumstances.

Can Pyrex Dishes Go Straight From The Freezer To The Microwave?

Pyrex dishes can go from the freezer to the microwave, but it is important to take precautions to avoid thermal shock. It is recommended to allow the container to thaw on the counter for several minutes before placing it in the microwave, as rapid temperature changes can cause the glass to shatter or explode.

Pyrex dishes are made of tempered glass, which can withstand high temperatures, but it is still important to exercise caution. Additionally, it is important to note that while Pyrex dishes are microwave safe, the switch to soda-lime glass lowered their heat tolerance, making them slightly more dangerous to use.

Can You Use Pyrex Lids In The Microwave?

Pyrex lids are designed to be microwave-safe as long as proper usage instructions are followed.

The lids are heat-resistant and can withstand high temperatures, but caution must be exercised to avoid the thermal shock that can cause the cover to break or deform. When microwaving food, the Pyrex lid should be placed on top without closing the latches to allow steam to escape.


Pyrex is considered to be microwave safe under certain conditions. Pyrex glass is known to be heat-resistant, durable, and suitable for cooking, and it is also plastic-free, non-porous, stain-resistant, and does not absorb food flavors or odors.

However, it is essential to note that Pyrex products in the USA or China are made of tempered soda lime glass, which differs from the borosilicate glass used in French and vintage Corning Glass Works products.

To ensure the safest use of Pyrex in the microwave, it is recommended to look for the PYREX® logo spelled with capital letters, indicating borosilicate glass, or to check the country of origin. Proper use and handling of Pyrex glassware are also essential to avoid thermal cracks and breaks.

Do you have any questions about is Pyrex microwave safe? Let us know in the comments below.

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